Jack N' Jill Kids Tickle Tooth Sonic Toothbrush Replacement Heads 2 pack are designed to fit on your existing Jack N' Jill Kids Tickle Tooth Sonic Electric Toothbrush. The Replacement Heads 2-pack comes with one round replacement head for babies ages 0-18 months and one oval replacement head for children 18 months and older. Bristles are extra soft to be gentle on little teeth. Tickle Tooth Replacement Heads are recyclable and BPA-free.